I do not want to sound professional by way of definitions here but just to give as much as possible a graphic view of how the two keywords, gambling and betting, relate in the world of sports.
Gambling generally refers to an activity where money or something of material value is set aside for two parties to predict the outcome of an event and the one whose prediction coincides with the income takes the wager. The outcome of the event is evident within a short period of time. Gambling takes many forms including lottery, casinos and any other games of the like which leaves the winner getting additional money or something of higher value.
Betting is a contract usually between two parties, where it is agreed that any of the parties will forfeit money or something of material value if that party makes an incorrect prediction about an uncertain exit. The exact money or its value is known and it is most often contributed before the outcome of the prediction.
Is there really any difference between these two terms? Although we most often interchange the use of the terms gambling and betting, I personally see some slight difference. I see betting as a subset of gambling for the latter is a general term which does not connote any jurisdiction to be tendered in the courts should the need be.
Betting is most often found in various sports activities including NBA, MLB and NFL. People are really making regular incomes from bets and you will love you did.